Electronic pen having an ultrasonic wave controller

• US 20070046654A1
• Filed: 06/14/2006
• Published: 03/01/2007
• Est. Priority Date: 08/23/2005
• Status: Active Grant

• Current Assignee: NEC Display Solutions, Ltd. (NEC Corporation)
• Original Assignee: NEC Viewtechnology, Ltd.
• Inventors: Tomiya, Shu
• Granted Patent: US 7,842,893 B2
• Time in Patent Office: Days
• US Class Current: 345/179
• CPC Class Codes: G06F 3/03545 Pens or stylus
• CPC Class Codes: G06F 3/043 using propagating acoustic waves

Abstract

The present invention aims to provide an electronic pen that is able to prevent the reflection of an ultrasonic wave. An electronic pen according to the present invention has: a housing having a longitudinal axis and a write side tip along the longitudinal axis; at least an ultrasonic wave transmitter, the ultrasonic wave transmitter being arranged near the write side tip of the housing; and a controller for detecting a sensor orientation and for controlling transmission of the ultrasonic wave. The sensor orientation is an index that shows a rotational orientation of the housing about the longitudinal axis, the rotational orientation being directed at an ultrasonic wave sensor for receiving the ultrasonic wave that is transmitted from the ultrasonic wave transmitter. The controller selectively activates a part of the ultrasonic wave transmitter such that the ultrasonic wave is transmitted from the orientation which is directed to the sensor orientation.

Claims

1. An electronic pen comprising:

a housing having a longitudinal axis and a write side tip along said longitudinal axis;

at least an ultrasonic wave transmitter, said ultrasonic wave transmitter being arranged near said write side tip of said housing; and

a controller for detecting a sensor orientation and for controlling transmission of the ultrasonic wave,

wherein the sensor orientation is an index that shows a rotational orientation of said housing about said longitudinal axis, said rotational orientation being directed at an ultrasonic wave sensor for receiving the ultrasonic wave that is transmitted from said ultrasonic wave transmitter, and

wherein said controller selectively activates a part of said ultrasonic wave transmitter such that the ultrasonic wave is transmitted from the orientation which is directed to said sensor orientation.

2. The electronic pen according to claim 1,

wherein said ultrasonic wave transmitter includes a plurality of ultrasonic wave transmitting units around said longitudinal axis of said housing, said ultrasonic wave transmitting units being arranged at orientations that are different from each other, and

wherein said controller includes;

a sensor detecting section for detecting said sensor orientation; and

a unit selecting section for selectively triggering a part of said ultrasonic wave transmitting units such that only said ultrasonic wave transmitting unit that is arranged at the orientation that is relatively close to said sensor orientation is triggered, wherein said sensor orientation is detected by said sensor detecting section.

3. The electronic pen according to claim 1,

wherein said ultrasonic wave transmitter is arranged to surround said longitudinal axis of said housing, and

wherein said controller includes;

a sensor detecting section for detecting said sensor orientation; and

an ultrasonic wave limiter for limiting operation of a part of said ultrasonic wave transmitter, wherein the part is positioned at the orientation that is relatively away from said sensor orientation, wherein said sensor orientation is detected by said sensor detecting section.

4. The electronic pen according to claim 3,

wherein said ultrasonic wave limiter includes;

a plurality of pressing bodies which are arranged around said ultrasonic wave transmitter at orientations that are different from each other,

a pressing body selecting section for selecting said pressing body that is positioned at the orientation that is relatively away from said sensor orientation, wherein said sensor orientation is detected by said sensor detecting section, and

pressing body driving sections for pressing respective pressing bodies against said ultrasonic wave transmitter, wherein said pressing body is selected by said pressing body selecting section.

5. The electronic pen according to claim 1,

wherein said ultrasonic wave transmitter is arranged to surround said longitudinal axis of said housing, and

wherein said controller includes;

a plurality of pressing bodies that are arranged around said ultrasonic wave transmitter at orientations that are different from each other; and

supporting members for supporting said respective pressing bodies such that said pressing bodies are free to move in a vertically downward direction and that at least one of said pressing bodies presses said ultrasonic wave transmitter, wherein at least one of said pressing bodies presses is positioned near a vertically upward direction.

6. The electronic pen according to claim 1, further comprising:

an infrared ray transmitter for transmitting an infrared ray in synchronization with transmission of the ultrasonic wave that is transmitted by said ultrasonic wave transmitter.

7. An electronic whiteboard system comprising:

the electronic pen according to claim 1;

wherein the electronic pen further comprises an infrared ray transmitter for transmitting an infrared ray in synchronization with transmission of the ultrasonic wave that is transmitted by said ultrasonic wave transmitter;

at least two ultrasonic wave sensors that are configured to be arranged apart from each other on a writing surface, information being written on said writing surface by said electronic pen;

infrared ray sensors for receiving the infrared ray, said infrared ray sensors being configured to be arranged adjacent to respective ultrasonic wave sensors on said writing surface; and

a coordinate calculator for calculating coordinates of said electronic pen on said writing surface by calculating a difference between a time at which the infrared ray is received by said infrared ray sensor and a time at which the ultrasonic wave is received by said ultrasonic wave sensor for each pair of said infrared ray sensors and said ultrasonic wave sensors.

8. A projector system comprising:

the electronic pen according to claim 6;

and

a projector apparatus which is configured to project an image onto a writing surface, information being written on said writing surface by said electronic pen;

wherein said projector apparatus includes;

at least two ultrasonic wave sensors;

at least one infrared ray sensor for receiving the infrared ray, said infrared ray sensor being arranged adjacent to each ultrasonic wave sensor; and

a coordinate calculator for calculating three-dimensional coordinates of said electronic pen by calculating a difference between a time at which the infrared ray is received by said infrared ray sensor and a time at which the ultrasonic wave is received by said ultrasonic wave sensor for each ultrasonic wave sensor.

9. An electronic pen comprising:

a housing having a longitudinal axis and a write side tip along said longitudinal axis;

at least an ultrasonic wave transmitter, said ultrasonic wave transmitter being arranged near said write side tip of said housing; and

wherein a sensor orientation is detected, wherein the sensor orientation is an index that shows a rotational orientation of said housing about said longitudinal axis, said rotational orientation being directed at an ultrasonic wave sensor for receiving the ultrasonic wave that is transmitted from said ultrasonic wave transmitter, and

wherein a part of said ultrasonic wave transmitter is selectively activated such that the ultrasonic wave is transmitted from the orientation which is directed to said sensor orientation.